WO2007074957A1

WO2007074957A1 - Composition having antimicrobial activity, filter for indoor air quality applying the same and manufacturing method thereof

Info

Publication number: WO2007074957A1
Application number: PCT/KR2006/001605
Authority: WO
Inventors: Woo-Jae Kim; Nam-Hun Oh; Seung-Kyu Park; Jeong-Cheol Kim
Original assignee: Lg Household & Health Care Ltd.
Priority date: 2005-12-26
Filing date: 2006-04-28
Publication date: 2007-07-05
Also published as: KR20070068070A; KR100789556B1

Abstract

Disclosed are a composition having antimicrobial activity capable of preventing infections of various microbial species, a filter for indoor air quality using the composition and a manufacturing method thereof. The composition having antimicrobial activity according to the present invention includes Nano Silver zeolite in which silver nanoparticles are absorbed into zeolite powder; Houttuynia Cordata extract; and 2,4,4-trichloro-2-hydroxy diphenylether. The composition including the three components can be effectively used for the filter for indoor air quality for preventing various microbial infections since the composition exhibits a synergic antibacterial or antiviral effect on various microbial species including human and avian influenza viruses as well as various kinds of bacteria, fungi, etc.

Description

COMPOSITION HAVING ANTIMICROBIAL ACTIVITY,

FILTER FOR INDOOR AIR QUALITY APPLYING THE SAME

AND MANUFACTURING METHOD THEREOF

Technical Field

[1] The present invention relates to a composition having antimicrobial activity capable of preventing infections of microbial species, such as various kinds of bacteria, fungi and viruses, that can induce various diseases, a filter for indoor air quality using the composition and a manufacturing method thereof. Background Art

[2] In particular, increasing precautions have been taken against human and avian influenza viruses.

[3] Human influenza is one of prevalent respiratory diseases which are epidemic in the temperate regions nearly every winter. The influenza epidemics is a serious disease that increases rates of hospitalization and death of aged men and children due to the event of respiratory diseases and also causes some occupational setbacks to healthy persons, resulting in huge social/economic losses.

[4] Also, avian influenza is one of diseases with which most of birds and domestic fowls become easily infected, and the avian influenza viruses have a characteristic that they have more various serotypes than those of the Mammalia. For this purpose, the event of a novel influenza virus in the Mammalia has been mainly derived from the avian influenza viruses. In this case, the novel influenza virus has become a worldwide issue due to serious economical losses by the events of the viral infection of human beings as well as viral infection of domestic fowls and animals.

[5] As described above, there have been attempts to develop various prophylactic agents and therapeutic agents and take preventive measures against epidemics, etc so as to reduce damages caused by microorganism including various kinds of the viruses. In order to decrease possibility of infecting human with various microorganisms such as bacteria, fungi, viruses or the likes in indoor residential spaces, it is also necessarily required to develop a method for giving an antimicrobial activity to a filter for indoor air quality applied to household electric appliances such as an air conditioner, an air cleaner, a cleaner, etc.

[6]

Disclosure of Invention Technical Problem [7] Accordingly, the present invention is designed to solve the problems of the prior art, and therefore it is an object of the present invention to provide a composition having antimicrobial activity, the composition exhibiting a synergic antibacterial or antiviral effect on various microbial species including human and avian influenza viruses as well as various kinds of bacteria, fungi, etc.

[8] Also, it is another object of the present invention to provide a filter for indoor air quality exhibiting an effective antimicrobial activity when the filter is used for household electric appliances such as an air conditioner, an air cleaner, a cleaner, etc., and a manufacturing method thereof.

[9]

Technical Solution

[10] In order to accomplish the above object, the present invention provides a composition having antimicrobial activity including Nano Silver zeolite in which silver nanoparticles are absorbed into zeolite powder; a Houttuynia Cordata extract; and 2,4,4-trichloro-2-hydroxy diphenylether.

[11] In the composition of the present invention, the Nano Silver zeolite, the Houttuynia

Cordata extract and the 2,4,4-trichloro-2-hydroxy diphenylether preferably have contents of 1 to 30 parts by weight, 0.01 to 10 parts by weight and 0.1 to 20 parts by weight, respectively.

[12] In order to accomplish the above object, the present invention also provides a filter for indoor air quality including the above-mentioned composition having antimicrobial activity; and a support having a predetermined area in contact with the air and fixing the composition.

[13] Such a filter for indoor air quality may be manufactured according to a method including (Sl) dispersing the composition having antimicrobial activity as defined in any one of claims 1 to 5 in a solvent to prepare a coating solution; (S2) applying the prepared coating solution to a support having a predetermined area in contact with the air by employing a spraying method or a dipping method; and (S3) removing the solvent from the product of the step (S2).

[14] Hereinafter, the present invention will be described in more detail.

[15] Generally, there are specific mechanisms concerning antimicrobial activity such as antibacterial or antiviral activity. The inventors have found that three components have a synergic antimicrobial activity against microorganism when the three components, that are Nano Silver zeolite in which silver nanoparticles are absorbed into zeolite powder; Houttuynia Cordata extract; and 2,4,4-trichloro-2-hydroxy diphenylether, are used together, and therefore the present invention is based on the above-mentioned surprising fact. [16] In the composition having antimicrobial activity of the present invention, each of the components will be described in brief, as follows.

[17] Generally, inorganic compounds, whose ions are exchanged with silver or zinc metal and which are known to have antibacterial and antifungal characteristics, have been widely used as antibacterial materials which are effective in the fields of daily necessaries such as conventional dental creams, or cosmetics. In particular, silver- titanium dioxide (Ag-TiO ) component, so-called a Nano Silver compound in which silver is impregnated into titanium dioxide, has been widely used as an effective an- tibacterially-treated material in plastics, textiles or the likes, as well as daily necessaries. However, although the inorganic compounds has a bactericidal effect, they have disadvantages that their response time is slow and has almost no effect on killing of human or avian influenza viruses as well as an insufficient fungicidal activity.

[18] The Nano Silver zeolite in which silver nanoparticles are absorbed into zeolite powder, used in the composition of the present invention, preferably means a compound in which silver nanoparticles having a mean particle diameter of 2 to 10 nm are absorbed into zeolite powder having a mean particle diameter of 1 to 3 D using an ion exchange process. A predetermined content of metals including cooper (Cu), manganese (Mn) and zinc (Zn), which have an excellent effect on killing of various fungi and bacteria, are absorbed into the zeolite powder using an ion exchange process to induce their synergic effect, if necessary. In particular, the zeolite, into which the silver (Ag) and zinc (Zn) nanoparticles are absorbed at a content of 0.1 to 15 % by weight and which is prepared with the ion exchange process, has an excellent effect on the killing of various fungi and human and avian influenza viruses due to high ionic activities of silver and zinc. Generally, it has been known that silver ions have excellent antibacterial and antiviral effects when they are in the state of silver ion cluster having a valence of 1 to 5, and therefore the Nano Silver zeolite particularly preferably contains 2-10 nm silver ion cluster to exhibit the antibacterial and antiviral effects, as described above.

[19] Also, another effective component, Houttuynia Cor data extract, is extracted from a perennial herb Houttuynia Cordata in Saururaceae, and the Houttuynia Cordata is also referred to as Houttuynia cordata Thunb. in the Korean Encyclopedia. The Houttuynia Cordata is mainly distributed over the Southeast Asia and, in particular, Japan, and grows in shady and wet mountains in Korea. The herb Houttuynia Cordata has been widely used as a medicinal plant and known to have a superior effect on prevention and treatment of diseases in the modern peoples which are exposed to serious environmental contaminations and various pollutions in their everyday lives, and therefore the Houttuynia Cordata has come to the spotlight as a marvelous herb and its medical action has been known to be excellent. The herb Houttuynia Cordata has excellent effects on beauty, body weight control and removal of poisonous matters from the body, and includes decatnoyl acetalehyde and quercitrin flavonoid compounds as major components. The Houttuynia Cordata extract may be obtained with a conventional extraction method, for example by being extracted from Houttuynia Cordata with an extraction solvent, followed by undergoing decompression and concentration processes, the extraction solvent being selected from the group consisting of lower alcohols having 1 to 4 carbon atoms such as ethanol, methanol, propanol, butanol, ethylglycol, prophyleneglycol, 1,3-butyleneglycol and the like, ethylacetate, acetone, water, hexane, etc., which are used alone or in combinations thereof. Ethanol is the most preferably used as the extraction solvent.

[20] Also, it has been known that, as the other effective component of the composition according to the present invention, 2,4,4-trichloro-2-hydroxy diphenylether (so-called, referred to as triclosan) particularly exhibits potent antibacterial and antifungal effects on various bacteria and is non-toxic to human. It has been known that the component has effects of suppressing bad smells by eliminating bacteria giving out bad smells as well as preventing proliferation of bacteria and reducing infections by microorganisms.

[21] In the composition having antimicrobial activity according to the present invention, the Nano Silver zeolite, the Houttuynia Cordata extract and the 2,4,4-trichloro-2-hydroxy diphenylether preferably have contents of 1 to 30 parts by weight, 0.01 to 10 parts by weight and 0.1 to 20 parts by weight, respectively.

[22] A filter may be manufactured by fixing the composition having antimicrobial activity, including the above-mentioned components, to a conventional support having a predetermined area in contact with the air, for example a support including fibrous non- woven fabric having a relatively large specific surface area, cellulose paper, mesh composed of metallic components such as alumina, foam composed of ure thane resins, prefilter mesh composed of propylene resins, various HEPA filters for collecting dusts, etc. And, the filter can exhibit an antimicrobial activity if it is used as a filter for indoor air quality in the household electric appliances such as an air conditioner, an air cleaner, a cleaner, etc., as described above. Because the triclosan has a binding activity by itself, it is almost unnecessary to use additional binder resin to fix the effective components to the support. This can be a big merit because, when various filter supports are coated with conventional Nano Silver titanium dioxide, green tea extracts such as catechin, organic or inorganic antibacterial materials such as chitosan, etc., certain binders, including ure thane resin, ethyl vinylacetate, vinyl acetate, acrylic adhesives, cellulose derivatives, etc., should be necessarily used in a large amount, which declines antibacterial activity of the antibacterial materials.

[23] The method for manufacturing a filter for indoor air quality using the above- mentioned composition having antimicrobial activity will be described in detail, as follows.

[24] The above-mentioned composition having antimicrobial activity is dispersed in a solvent to prepare a coating solution (Sl). Alcohol or glycol is preferably used as the solvent since it is highly compatible with the above effective components.

[25] Subsequently, the prepared coating solution is applied to a support having a predetermined area in contact with the air using spray coating, gravure printing and dipping processes (S2). A kind of the support may include, but is not particularly limited to, the above-mentioned non- woven fabric, or supports of plastic materials and metallic materials.

[26] Finally, a filter for indoor air quality, in which the composition having antibacterial activity is fixed to the support, may be manufactured by removing the volatile solvent from the product of the step (S2)(S3).

[27]

Best Mode for Carrying Out the Invention

[28] Hereinafter, preferred embodiments of the present invention will be described in detail. However, the description proposed herein is just a preferable example for the purpose of illustrations only, not intended to limit the scope of the invention, so it should be understood that other equivalents and modifications could be made thereto without departing from the spirit and scope of the invention.

[29]

[30] Preparation of Triclosan. Houttuynia Cordata Extract and Nano Silver

Zeolite

[31] In order to prepare a Houttuynia Cordata extract, 500 ml of ethanol was added to

100 g of chopped Houttuynia Cordata, and then the resultant mixture was macerated for 48 hours at room temperature, and filtered with a Whatman No. 2 filter. The filtered extract was concentrated at 50 ⁰C under a reduced pressure to obtain a Houttuynia Cordata extract.

[32] Meanwhile, it has been known that the triclosan exhibits potent antibacterial and antifungal effects on various bacteria and is non-toxic to human. It has been known that the component has effects of suppressing bad smells by eliminating bacteria giving out bad smells as well as preventing proliferation of bacteria and reducing infections by microorganisms. Therefore, powdery triclosan was purchased from Ciba (Switzerland).

[33] Meanwhile, the Nano Silver zeolite, which was manufactured using an ion exchange process, was purchased from Fuji Chemical (Japan).

[34]

[35] Preparative example of Filter for Indoor Air Quality [36] Based on the components and their contents of Examples and Comparative examples as listed in the following Table 1, the Nano Silver zeolite (hereinafter, referred to as "AZZ"), the Houttuynia Cordata extract and the triclosan compound were mixed together, and ethanol was added thereto, and then the resultant mixture was stirred, heated and cooled in a mixer to prepare a coating solution. Then, a non- woven filter support was immersed in the prepared solution for 5 to 10 minutes, put into a hot air drying oven and sufficiently dried at 60 to 90 ⁰C for 2 hours to remove a volatile ethanol component, and then cooled and dried under an ambient condition to prepare a non- woven filter.

[37] Table 1

' cs

Balance Bai«nc( Balance

[38] Effects of the non- woven fabric filer materials on the avian and human influenza viruses were tested using the compositions of the Examples and Comparative examples. The results are listed in the following Tables 2 and 3.

[39] [40] Preparation of Influenza Virus and Measurement of its Activity [41] In order to determine effects of the compositions on the influenza viruses, two test subjects of one avian influenza virus {A/Chicken/Korea/ms 96/96(H5Nl)} and one human influenza virus {/Korea/ms 96/96(H3N2)} were tested in the present invention.

[42] An MDCK(Mardin-Darby Canine Kidney) animal cell was used as a host cell required for culture of the influenza viruses. A medium used for the culture of the MDCK cell was a medium prepared by adding 10 % fetal bovine serum and 0.27 % sodium bicarbonate to a minimum essential medium (MEM), adding 0.005 % gentamicin to prevent fungal contamination and sterilizing the resultant medium with a filtration system. 15 ml of the MEM solution was divided into vials (size: 75 D) for animal cell culture, and inoculated with the MDCK animal cell, and then cultured at 37 ⁰C for 3 ~ 4 days in a CO incubator. A culture supernatant was removed off when the MDCK animal cell was grown to the range of 90 % or more, and then inoculated with the influenza viruses. Also, 15 ml of a fetal bovine serum and gentamicin-free MEM solution was added and cultured at 33 ⁰C for 3 ~ 4 days in a CO incubator, and, when 90 % of the MDCK animal cell was died, the resultant culture solution was then centrifuged to obtain an MDCK cell-free virus solution.

[43] And, a MEM solution was divided in an amount of 100 D into a 96- well plate, inoculated with 100 D of a stock solution containing 10 cell/ml of the MDCK cell, and incubated at 37 ⁰C for 3 - 4 days in a CO incubator. A culture supernatant was removed from the 96-well plate in which the MDCK animal cell was grown, and the influenza virus solution was sequentially diluted with a gentamicin-free MEM solution, and then the 96-well plate was inoculated with 100 D of the diluted influenza virus solution to determine viral activities as a minimum dilution ratio of the influenza virus solution which does not cause a lesion in the MDCK animal cell.

[44] [45] Activity Test on Avian Influenza Virus [46] A non-woven fabric filter (25 cm in size) was coated with 0.01 ~ 10 g of the compositions having the components and their contents of the Examples and the Comparative examples, as described in following Table 2, and the coated non- woven fabric filter was cut into small 3x3 mm test samples. Then, each of the test samples, which were coated with the increasing contents of the composition, was reacted with the avian influenza virus for 1 hour, and then fertilized eggs were infected with the resultant reaction solutions to determine whether the avian influenza virus dies or survives in the fertilized eggs. The results are listed in the following Table 2. As listed in the Table 2, it was revealed that the filters, coated with the three components- containing compositions according to the present invention, have an excellent effect on inactivation of the avian influenza virus in the air.

[47] Table 2

[48] In Table 2, "-" represents the death of avian influenza viruses, and "+" represents the survival of avian influenza viruses. [49] [50] Activity Test on Human Influenza Virus [51] A non-woven fabric filter (25 cm in size) was coated with 0.01 ~ 10 g of the compositions having the components and their contents of the Examples and the Comparative examples, as described in following Table 2, and the coated non- woven fabric filter was cut into small 3x3 mm test samples. Then, each of the test samples, which were coated with the increasing contents of the composition, was reacted with the human influenza virus for 1 hour, and then the previously cultured MDCK cell was infected with the resultant reaction solution to determine whether the human influenza virus dies or survives in the reaction solution. The results are listed in the following Table 3. As listed in the Table 3, it was revealed that the filters, coated with the three components -containing compositions according to the present invention, have an excellent antiviral effect on the human influenza virus.

[52] Table 3

[53] In Table 3, "-" represents the death of avian influenza viruses, and "+" represents the survival of avian influenza viruses.

[54] [55] Test of Antibacterial Effect on Bacteria [56] In order to determine an antibacterial effect of the non- woven fabric filters prepared with the compositions of the present invention and the compositions of the Comparative examples, a BHI agar plate was inoculated with three representative bacteria including Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa, and incubated at 37 ⁰C for 24 hours in an incubator.

[57] A non-woven fabric filter (25 cm in size) was coated with 0.01 ~ 10 g of the effective components as described in the Examples and the Comparative examples, and then the coated non- woven fabric filter was cut into small 3x3 mm test samples, as described above. Then, the resultant test samples were transferred into 10 ml of sterile saline, respectively, and the previously incubated bacteria were added thereto to a density of 1.0 x 10 /ml. Subsequently, the flask containing both of the bacteria and the filter was incubated at 37 ⁰C for 18 hours in a shaking incubator with a rotary speed of 100 rpm. 18 hours after the incubation, 1 ml of the reaction solution was taken from the flask, and the number of the survived cells was counted to determine antibacterial effects as a function of the number of the survived bacteria to the initial number of the inoculated bacteria. The results are listed in the following Tables 4 to 6.

[58] [59] 1) Antibacterial Effect on E. coli [60] Initial No. of Inoculated E. coli: 1.0 x 10⁶/ml [61] No. of Survived E. coli after 18 hours: (unit amount: 1 ml) [62] Table 4

Compo s i t ion

E co l i

•

[63] 2) Antibacterial Effect on P. aeruginosa

[64] Initial No. of Inoculated P. aeruginosa: 1.0 x 10⁶/ml

[65] No. of Survived P. aeruginosa after 18 hours: (unit amount: I mI)

[66] Table 5

(% by 10 ,> '' K 1 K 0 ! ,' (I O U

1 100 JOO 100 100 100 100 100

<> 100 100 100 100 100 100 U)O r<<ιπi[j Oi 3 100 100 100 100 100 300 100

/; 100 100 100 !OO 100 U)O 100 ^■>

CoMipar.j f j yt 2 50 40 /0 0 0 0 0

[67] 3) Antibacterial Effect on S. aureus

[68] Initial No. of Inoculated S. aureus: 1.0 x 10⁶/ml

[69] No. of Survived S. aureus after 18 hours: (unit amount: 1 ml) [70] Table 6

!i1 » (S by U) O 10 9 > K '^■ ? o b r O , ? "S Ol,> I ! ! </,<

00 1( 0 loo- IuO IOO 130 OJ 100 100 no IOO JOO 100 ¹O)

/ IRl]I I ' : ¹ OO 100 .00 iOO 100 100 ^"1O')

I ^"• oo 100 .00 100 100 OO

6 ,><ii c u i 00 U)O ,00 J OO JOO 'OO Ύ> ,'^■>

% )0 O O

¹ ( inp f a! ι v( iOO KK) 91 O O 100 100 9b O O M) ,0

O O

[71] Test of Antifungal Effect on Fungi [72] In order to determine an antifungal effect of the non-woven fabric filters prepared with the compositions of the present invention and the compositions of the Comparative examples, a PDA agar plate was inoculated with two fungi including Aspergillus niger and Penicillium citrinum, and incubated at 30 ⁰C for 72 hours in an incubator.

[73] A non-woven fabric filter (25 cm² in size) was coated with 0.01 ~ 10 g of the effective components as described in the Examples and the Comparative examples, and then the coated non- woven fabric filter was cut into small 3x3 mm test samples, as described above. Then, the resultant test samples were transferred into 10 ml of sterile saline, respectively, and the previously incubated bacteria were added thereto and cultured to a density of 1.0 x 10⁶/ml. Subsequently, the filter samples were added to the incubated fungi, and then incubated at 37 ⁰C for 48 hours in an incubator. 48 hours after the incubation, the sizes (mm) of clear zones, formed around the filter samples on the medium, were measured to determine antifungal effects on the fungi. The results are listed in the following Tables 7 and 8.

[74] [75] 1) Antifungal Effect on Aspergillus niger [76] Table 7

[77] 2) Antifungal Effect on P. citrinum

[78] Table 8

~^~ Component s (^■% bj ■se λφi ) if _ε ^r~> g - R 0 h „' O i ₅,

( _'jiaoos it iop j J O S 6 "3 4 _>

J O I 4 i

K) I i 1

1 9 2 2

P el if mum 6 b 2 1 S 1 j S i 1 - i 1 _ c xaiBp 'c 3

4 ϊ 2 I

[79] As listed in Tables 4 to 8, it was revealed that the filter containing all the three components according to the present invention has excellent antibacterial and antifungal effects on various kinds of bacteria and fungi.

[80]

Industrial Applicability [81] As described above, the composition including Nano Silver zeolite in which silver nanoparticles are absorbed into zeolite powder; a Houttuynia Cordata extract; and 2,4,4-trichloro-2-hydroxy diphenylether according to the present invention has an excellent efficiency in inactivation of the human and avian influenza viruses as well as a synergic antimicrobial effect on various kinds of bacteria and fungi. Accordingly, such a composition having antimicrobial activity can be effectively used to exhibit an effective antimicrobial activity when the composition is applied to the filter for indoor air quality in the field of household electric appliances such as an air conditioner, an air cleaner, a cleaner, etc. [82] Also, the 2,4,4-trichloro-2-hydroxy diphenylether among the above effective components can serve as a binder resin by itself. Therefore, the composition is more useful to prevent reduction in the antimicrobial activity caused by additional use of a binder resin since it is unnecessary to use the binder resin to fix the effective components to the support.

Claims

[1] A composition having antimicrobial activity, comprising Nano Silver zeolite in which silver nanoparticles are absorbed into zeolite powder; a Houttuynia Cordata extract; and 2,4,4-trichloro-2-hydroxy diphenylether.

[2] The composition having antimicrobial activity according to claim 1, wherein the Nano Silver zeolite, the Houttuynia Cordata extract and the 2,4,4-trichloro-2-hydroxy diphenylether have contents of 1 to 30 parts by weight, 0.01 to 10 parts by weight and 0.1 to 20 parts by weight, respectively.

[3] The composition having antimicrobial activity according to claim 1, wherein the Nano Silver zeolite is formed by absorbing silver nanoparticles having a mean particle diameter of 2 to 10 nm into zeolite powder having a mean particle diameter of 1 to 3 D.

[4] The composition having antimicrobial activity according to claim 1, wherein zinc nanoparticles are further absorbed into the Nano Silver zeolite.

[5] The composition having antimicrobial activity according to claim 1, wherein the Houttuynia Cordata extract is extracted with at least one solvent selected from the group consisting of lower alcohol having 1 to 4 carbon atoms, ethylacetate, acetone, water and hexane.

[6] A filter for indoor air quality comprising: the composition having antimicrobial activity as defined in any one of claims 1 to 5; and a support having a predetermined area in contact with the air and fixing the composition.

[7] A method for manufacturing a filter for indoor air quality, the method comprising:

(51) dispersing the composition having antimicrobial activity as defined in any one of claims 1 to 5 in a solvent to prepare a coating solution;

(52) applying the prepared coating solution to a support having a predetermined area in contact with the air by employing a spraying method or a dipping method; and

(53) removing the solvent from the product of the step (S2).

[8] The method for manufacturing a filter for indoor air quality according to claim 7, wherein the solvent is one selected from the group consisting of ethanol, a glycol compound, and a mixture thereof.